The socialite is set to begin a 45-day jail term on June 5 and some of the ladies she'll be locked up with at California's all-female Century Regional Detention Facility have started to let her know she won't be a welcome guest.

A source close to Hilton tells Life & Style magazine the hotel heiress started receiving death threats on her MySpace.com page the day after she was sentenced to serve time for violating her probation by driving with a suspended license.

The insider says, "These maniacs have been writing, 'We're going to get you,' and, 'I'm going to kill you.' It's horrifying.

"One person wrote that she's going to steal Paris' shoes when she gets to jail--and if Paris argues, she'll be beaten to a pulp."

In an exclusive interview with the publication, Hilton admits, "I'm very scared right now."

Hilton, who is appealing her sentence, has learned she'll be housed away from the bulk of inmates at the jail for her protection.